Ice maker

ABSTRACT

There is disclosed an icemaker for installation in a household refrigerator. An improved ice ejector mechanism is mounted beneath the mold to conserve freezer space. An increase in ice production capability is provided by providing a turbulent cold air flow path around the exterior of the ice mold. Means are provided to prevent cold air passage across the mold during ice harvesting. The icemaker may be disposed adjacent either of the side walls or the back wall of the freezer.

United States Patent 1191 Frazier Nov. 26, 1974 [54] ICE MAKER 3,727,4274 1973 Eyman, Jr. et a1 74/50 x [75] Inventor: Lauren L. Frazier,Louisville, Ky.

Primary Examiner Meyer Perlin Asslgneei Electric p y Attorney, Agent, orFirmFrank L. Hart; Francis H.

Lou1sv1lle, Ky. B005 [22] Filed: Dec. 19, 1973 21 Appl. No.: 425,989[571 ABSTRACT Related US Application Data There is disclosed an icemakerfor installation in a Division of Ser No 318 715 Dec 27 972 householdrefngerator. An improved 1ce e ector mechanism 1s mounted beneath themold to conserve freezer space. An increase in ice production capability62/35;g is provided by providing a turbulent Cold air flow path 58 d 51c74/50 around the exterior of the ice mold. Means are pro- 1 0 earcvided to prevent cold air passage across the mold during ice harvesting.The icemaker may be disposed ad- [56] UNITE S S E X FES SZQFENTS jacenteither of the side walls or the back wall of the freezer.

3,058,361 10/1962 Freeborn 74/50 3,163,018 12/1964 Shaw 62/353 x 5Cla'ms, 6 Drawmg PATENTL @3426 I974 SHEH 10F 3 PATENTEDF-QGVZEISM 08SHEH 3 OF 3 P101 no.4

ICE MAKER This is a division of application Ser. No. 318,715, filed Dec.27, 1972.

The provision of icemakers in household refrigerators is quite common.Typical icemakers proposed by the prior art are found in US. Pat. Nos.3,163,017 and 3,163,018. In the commercial design of these devices, theice mold comprises a cast aluminum block having heat exchange finsthereon. Accordingly, the ice mold of the prior art is relativelymassive thus requiring substantial material expense. In thesedisclosures, an ice mold having a plurality of upwardly facing ice cubecavities is disposed beside a motor and linkage mechanism for ejectingice pieces from the cavities. Although these icemakers have provedacceptable, certain improvements in mounting flexibility, spaceconservation, ice making efficiency and ice harvesting efficiency arecontemplated by this invention.

It has been learned that greater mounting flexibility and spaceconservation can be achieved by positioning the motor and linkagemechanism for the ice ejector below the. ice mold rather than beside thesame.

Ice making efficiency of the device of this invention is improved overthat of the prior art by providing a cold air passage around the mold.Turbulent cold air movement in the passage results in improved heattransfer across the mold thereby resulting in greater ice production.

Ice harvesting efficiency is improved in the device of this invention byclosing the cold air passage at the inception of ice harvesting therebyminimizing heat transfer across the mold during the ice harvestingcycle. Consequently, a lower capacity heater may be utilized to warm themold in order to free the ice pieces for ejection. Ice harvestingefficiency is also improved by the design of the ejector linkagemechanism.

It is an object of this invention to provide an ice maker having greatermounting flexibility, increased ice production capability, increased iceharvesting efficiency and achieving greater space utilization.

In summary, one aspect of this invention comprises an icemaker includinga mold having an inner surface providing ice piece forming cavities andan outer surface; a housing around the mold, the housing and the outermold surface defining therebetween a serpentine path of cold airmovement for abstracting heat from the mold; and means for harvestingice from the mold.

Another aspect of this invention comprises a cold storage appliancehaving a freezing compartment defined by a plurality of walls and meansfor circulating cold air in the compartment; and an ice maker, in thecompartment. comprising a mold having an inner surface providing icepiece forming cavities and an outer surface; a housing, independent ofthe compartment walls, around the mold and defining with the outer moldsurface a path of cold air movement; and means forharvesting ice piecesfrom the cavities including a heater for warming the inner mold surfaceand means for removing ice pieces from the cavities.

A further aspect of this invention comprises an icemaker including amold providing ice piece forming cavities, means providing a cold airpassage in heat exchanging relation with the mold, means operativeduring ice harvesting for removing ice from the mold including a heaterfor warming the mold, and means operative during harvesting forrestricting the passage.

Other aspects, features and advantages of this inven tion will becomemore apparent hereinafter.

IN THE DRAWINGS FIG. 1 is a cross sectional view of a cold storageappliance illustrating the icemaker of this invention in one operativeconfiguration thereof;

FIG. 2 is an enlarged front elevation view of the icemaker of thisinvention, certain parts being broken away for clarity of illustrationand illustrating the icemaker during the icemaking cycle;

FIG. 3 is a broken view similar to FIG. 2, certain parts being omittedfor clarity, illustrating the icemaker at the inception of the iceharvesting cycle;

FIG. 4 is a view similar to FIG. 3 illustrating the ejector mechanism inthe ice piece ejection position;

FIG. 5 is a horizontal cross sectional view of the icemaker of FIGS. 1-4taken substantially along line S5 of FIG. 2 as viewed in the directionindicated by the arrows; and

FIG. 6 is a schematic view of a typical electrical control circuit whichmay be utilized with the icemaker of this invention.

Referring to FIG. 1, the icemaker 10 of this invention is illustrated aspositioned in the freezing compartment 12 of a cold storage appliance.The freezing compartment 12 is defined by a bottom wall 14, side walls16, a back wall 18 and an open front which is closed bya a conventionaldoor (not shown). Opening through the back wall 18 is a duct 20 havingtherein a fan 22 for circulating cold air through the compartment 12.The fan 22 is typically controlled by a suitable thermostat (not shown)for starting and stopping cold air circulation in the compartment 12 inresponse to temperature therein. As will become more fully apparenthereinafter, the fan 22 comprises means for circulating cold air in thecompartment 12 through the icemaker 10.

In order to assure that cold air passes through the icemaker 10 in theappropriate direction and in order to assure a substantial quantity ofcold air moving through the icemaker 10, there is preferably provided afitting 24 secured to the back wall 18 adjacent the duct 20. The fitting24 acts to deliver a predetermined ratio of air from the fan 22 to aflexible conduit 26 connected to the icemaker 10.

For purposes of illustration, the icemaker 10 is illustrated adjacentthe left side wall of the compartment 12 as viewed from the open frontwith an ice storage container 28 adjacent thereto. A prototype of theicemaker 10 is approximately 2-V2 inches wide X 7- /4 inches high X 9inches deep. Accordingly, in many installations, the icemaker 10 may beplaced on the freezer bottom wall with a shelf thereabove. As will bemore fully apparent hereinafter, the icemaker 10 is unit handled and maybe positioned adjacent either side: or the back of the compartment 12.

Referring to FIGS. 2-6, the icemaker 10 comprises as major components amold 30, a housing or baffle 32 defining with the mold 30 an undulatingor serpentine cold air passage 34, ice harvesting means 36 including aheater 38, an ejector 40, driving means 42 and a linkage 44interconnecting the driving means 42 and the ejector 40, a valve 46 forrestricting the cold air passage 34 during harvesting, and a circuit 48for controlling operation of the various components during the icemakingand ice harvesting cycles.

The mold 30 includes an inner surface 50 providing a plurality ofupwardly facing ice piece forming cavities 52. For all practicalpurposes, the inner mold surface 50 is substantially the same asillustrated in US. Pat. Nos. 3,163,107 and 3,331,215. The mold 30 alsoincludes an outer mold surface 54 of substantially the sameconfiguration as the inner surface 50. The mold 30 is accordingly a thinwall mold as contrasted with the disclosures of the prior art referredto previously. The outer mold surface 54 presents an undulating surfacerather than a planar surface as shown in the prior art. The mold 30 alsoincludes a bottom wall 56 spaced below the bottom of the cavities 52(FIG. 4) in order to accommodate the ejector 40 in the icemakingposition thereof as shown in FIG. 2. The mold 30 may also comprise a topwall 58 for securement to the frame 60 of the icemaker 10.

Referring to FIGS. 1 and 2, there is provided a filling trough 62connected to a suitable water line 64 passing through the side wall 16of the freezing compartment 12. As will be apparent from FIG. 2, thefilling trough 62 may be connected on either end of the icemaker 10which enhances mounting flexibility thereof. Water flowing through theconduit 64 and the filling trough 62 into the mold 30 is controlled by avalve 66 (FIG. 6) having a solenoid 68 which, when energized, opens thevalve 66 to permit water to enter the filling trough 62 and mold 30.Since the opening into the filling trough 62 may be through the sidewall, as illustrated, or through the end wall, mounting flexibility isfurther enhanced.

The housing 32 is captivated by the frame 60 between openings 70, 72therein and is in surrounding relation to the mold 30. The direction ofair movement along the passage 34 depends, of course, upon the naturalcirculation pattern within the freezing compartment 12 or the inducedcirculation pattern afforded by the fitting 24 and the conduit 26. Forpurposes of illustration, air flow is illustrated from right to left inFIG. since it is desirable that the thermostat 74 be in heattransferring relation with the downstream ice forming cavity 52.

The housing 32 comprises side walls 76, 78 which undulate in anarrangement complementary to the undulations in the mold 30 therebyproviding the undulating or serpentine air flow passage 34. Theconfiguration of the air flow passage 34 and the distances between themold 30 and the side walls 76, 78 are designed to achieve turbulent airflow in the passage 34 at volumetric air flows between 1 and CFM.Turbulent air flow in the passage 34 is highly desirable to avoid deadair spaces in the areas 80 between the ice piece forming sections. Thehousing 32 also comprises a bottom wall 82 underlying the mold 30 asseen most clearly in FIGS. 3 and 4.

Testing of various prototypes of this invention has revealed interestingdata. In an early prototype of the invention with a housing havingplanar side walls rather than undulating side walls with the cold aircirculating fan on continuously, the elapsed time from filling of theice piece cavities with water to freezing of the ice pieces was greaterthan 60 minutes. By incorporating means on the baffle side walls tocreate a serpentine cold air flow path and thereby provide turbulent airflow reduced the fill-to-freeze time to 40 minutes. It will beappreciated that the ice mold 30 and baffle 32 of this invention aresubstantialy less expensive than the cast aluminum ice molds of theprior art. This is primarily the result of a lesser quantity of materialin the mold 30 and the housing 32 and greatly simplified configuration.

The heater 38 comprises part of the ice harvesting means 36. For reasonsmore fully pointed out hereinafter, the heater 38 is a low powerelectrical resistance element in heat exchanging relation with the mold30. After the thermostat 74 has sensed that the temperature in thedownstream ice piece cavity 52 has declined to a predetermined value,the thermostat 74 closes. If the stop-start switch 84 is closed, as willbe explained more fully hereinafter, the heater 38 is energized tocommence the ice harvesting operation.

The ice piece ejector 40 is illustrated as being of generallyconventional configuration and is quite similar to that disclosed in US.Pat. No. 3,163,018. The ejector 40 accordingly comprises a plurality ofpiston-like plates 86 formed integrally with the top of a thin elongatehorizontal bar 88 which passes between the ice forming cavities. Anejector rod 90 is secured to the ejector 40, as by a screw 92. The rod90 is mounted by a bushing 94 in the bottom of the mold 30 for generallyvertical movement. The bushing 94 includes one or more O-rings 96 forsealing against the rod 90. The bushing 94 is threaded into a collar 98which is held by a clamp 100. In contrast with the amount of machiningrequired in prior art ice molds, the only machining required in the mold30 is the aperture in which the bushing 94 fits.

The driving means 42 comprises an electric motor 102 and a gear box 104of conventional design. The gear box 104 provides a rotatable output 106drivably connected to the linkage 44 for converting rotary motion of theoutput 106 into reciprocation of the ejector rod 90.

The linkage 44 comprises an enlarged hub 108 having thereon a crank orcam 110 spaced from the axis of the output 106. The cam 110 convenientlycomprises a screw 112 threaded into the hub 108 and a roller 114 mountedfor rotation thereon. The cam 110 is captivated in a generallyhorizontal slot 116 provided by a yoke 118 which is rigid with theejector rod 90. The yoke 118 is rigid with a framework 120 which isconstrained for vertical movement by a rod 122 passing through anopening 124 in the framework 120. It will accordingly be seen that thelinkage 44 is illustrated as a comprising a Scotch yoke.

FIGS. 2-4 illustrate respectively the icemaking position of the icemaker10, the initiation of the ice harvesting cycle and the termination ofthe ice harvesting cycle. As the motor 102 is energized from theposition of FIG. 2, the output 106 rotates thereby revolving the cam 110about the axis of the output 106. Revolution of the cam 110 causes theyoke 118 to move vertically as constrained by the rod 122.

The motor 102 and the heater 108 are energized substantiallysimultaneously. After an initial lost-motion movement of the linkage 44,the motor 102 stalls until the heater 38 melts a film of ice immediatelyadjacent the inner mold surface 50. As the heater 38 breaks the bondbetween the ice and the mold 30, the motor 102 begins movement therebyelevating the ejector 40. Consequently, the greatest force requiredduring the ice harvesting operation is at the initiation of ejectormovement. Accordingly, the linkage 44 is preferably designed to generatethe greatest force on the ejector rod 90 at the inception of upwardmovement thereof. An analysis of the linkage44 reveals that a largeupward force produced thereby occurs when the cam 110 lies in a sector126 adjacent the bottom of the path of movement of the cam 110.Accordingly, it is highly desirable that the linkage 44 commence iceharvesting movement in the sector 126.

.To this end, the motor 102 is de-energized by the circuit 48 on thedownstroke of the ejector rod 90 and a biasing spring 128 is providedfor biasing the rod 90 to its lower position and assuring fulldownstroke movement thereof as shown in FIG. 2.

The ice harvesting means 36 also includes a feeler arm 130 for sensingthe quantity of ice in the container 28. The feeler arm 130 isillustrated as passing through the housing 32 and journalled by suitablebushings 132 therein. As shown best in FIG. 5, the feeler arm 130 isrigidly connected to a lever 134 which is in turn pinned to a member136. The member 136 is constrained by a bracket 138 for verticalmovement and includes, at the lower end thereof, a pair of switchactuating members 140 and 142. The switch actuating members 140, 142captivate a switch actuator 144 for the switch 84 illustrated in FIG. 6.

During ice harvesting the feeler arm 130 is raised out of the icecontainer 28 before ejection of the ice pieces and it thereafter dropsinto engagement with the ice pieces. To this end, there is provided anextension 146 underlying a bearing element 148 carried by the member136. As the linkage 44 is actuated, the framework 120 and the extension146 thereon are elevated into contact with the bearing element 148. Assuggested in FIG. 4, during each ice ejection cycle the extension 146elevates the member 136 thereby raising the feeler arm 130 substantiallyout of the container 28 and returns to the position as illustrated inFIG. 2, allowing member 136 to assume a position determined by theengagement of feeler arm 130 with the ice pieces.

As the container 28 fills with ice, the feeler arm 130 assumes a more orless horizontal position upon engaging the ice pieces. Ultimately, asthe container 28 fills, the switch actuating member 140 is held in anelevated position so that the switch actuator 144 opens the circuitleading to the motor 102 thereby preventing further harvesting of ice.As the container 28 is emptied, the feeler arm 130 again assumes a morenearly vertical position so that the switch actuating member 142 mayengage the switch actuator 144 and close the stop-start switch 84. Inthe alternative, the switch 84 may be of the normally closed type suchthat downward movement of the member 136 allows the switch actuator 144to return to the closed position.

An important part of the ice harvesting means 36 is the valve 46 forclosing or restricting the cold air passage 34. The valve 46 includes agate 150 mounted for movement in a suitable slot 152 between positionsopening and closing the passage 34. The gate 150 is manipulated betweenthese positions by an actuating arm 154. The actuating arm 154 ismovably mounted by a pivot connection 156 which is conveniently securedto the gear box 104. The free end of the actuating arm 154 is connectedto the gate 150 by a suitable lost-motion connection. A cam follower 158is mounted on a projection 160 extending from the arm 154. The follower158 is captivated in a camming groove 162 on the back side of the hub108. As shown in FIG. 2, the follower 158 is positioned by the cam track162 to depress the actuating arm 154 and thereby move the gate out ofthe air passage 34. Since FIG. 2 illustrates the icemaking cycle ofoperation, air flow through the passage 34 is unimpeded. At thecommencement of the ice harvesting cycle, the hub 108 is rotated towardthe position in FIG. 3. The cam follower 158 is moved laterally of thepivot connection 156 thereby raising the actuating arm 154 and movingthe gate 150 to the closed position. In the configuration of FIG. 3, itwill be apparent that air flow through the passage 34 stops. By closingthe valve 46, heat transfer from the inner mold surface 50 to the outermold surface 54 is greatly reduced.

The reduction of heat transfer from the inner mold surface 50 the outermold surface .54 has two important advantages. With the valve 46 closed,the heater 38 needs only to warm the mold 30 sufficiently to break theice adhesion bond. With the gate 46 open and cold air flowing throughthe passage 34., the heater 38 would necessarily be of greater capacitysince a substantial quantity of heat would be transferred to the movingair stream rather than to the mold 30. Accordingly, a low power heatermay be utilized. In prototypes of this invention, heaters having 3040watt capacity have proved satisfactory compared to 180 watt heaters usedon presently commercially available icemakers. An important practicalsidelight of this improvement in operating efficiency is that theheretofore conventional overheat safety thermostat, which is normally inseries with the thermostat 74, may be deleted since the maximumtemperature rise of low power heaters is within the maximum allowabletemperature rise for materials used in the icemaker 10.

There is another important advantage in ice harvesting efficiencyafforded by this invention. Referring to FIG. 3, it will be apparentthat the mold 30 is gaining heat immediately adjacent the heater 38 andgiving up heat away from the heater 38. By reducing heat transferefficiency during harvesting, the mold 30 does not need to be heated toas great a temperature to release the ice pieces in the cavities 52.Thus, there is a reduction in total heat input required of the heater38.

Because ofthe degradation of heat transfer efficiency during harvesting,more sophiscated design improvements become practical. For example,breaking the adhesion of the ice pieces in the end cavities creates agreater stress on the ejector 40 and operating assembly therefor becauseof the longer moment arm between the end cavities and the axis ofejector movement. This may be obviated, if desired, by controlling heatinput to break the adhesion bond in a particular sequence, for exampleend ice pieces first.

The switching mechanism 164 used in the control of the icemaker 10 issubstantially the same as illustrated in US. Pat. No. 3,163,018. Theswitching mechanism 164 comprises sequentially actuated switches 166,168. The switch 166 controls an energizing circuit for the motor 102while the switch 168 controls the solenoid 68 of the filling valve 66.The switches 166, 168 are conveniently ganged together and manipulatedby an actuator 170 having thereon a cam follower 172 which engages theperiphery 174 of the hub 108. The hub periphery 174 includes adepression 176 allowing selfbiased movement of the actuator 170 towardthe switch open position illustrated in FIG. 6.

At the termination of the icemaking cycle, the thermostat 74 closes. Ifthe feeler arm 130 senses a lack of ice in the container 28, the switch84 is closed. Thus, a circuit is completed to the heater 38 and themotor 102 thereby initiating the ice harvesting cycle. Until theadhesion bond between the ice pieces and the inner mold surface isweakened by the heater 38, the ejector 40 and rod 90 cannot moveupwardly. Since the slot 116 and the cam 110 constitute a lost-motionconnection, the hub 108 is free to rotate from the position shown inFIG. 2 toward the position shown in FIG. 3. This rotation of the hub 108initiates a plurality of functions including closing of the valve 46 andclosing of the switch 166.

The motor 102 stalls until the adhesion bond between the ice pieces andthe inner mold surface 50 is substantially weakened. The force imposedby the driving means 42 and linkage 44 is then sufficient to completebreakage of the adhesion bond and allow upward movement of the rod 90and ejector 40 toward the position illustrated in FIG. 4. As the icecubes eject from the mold 30, they engage a suitable deflector 178 andfall into the container 24. Continued rotation of the hub 108 causesdownward movement of the ejector 40 and rod 90 from the position shownin FIG. 4 toward the position shown in FIG. 2. During the heatingperiod, thermostat 74 opens so that when the follower 172 passes intothe depression 176, opening switch 166, the motor 102 and heater 38 arede-energized. The hub 108 begins to coast to a stop. Engagement of thecam 110 with the bias spring 128 causes the icemaker to come to rest inpreparation for an icemaking cycle.

As is apparent from FIGS. 1 and 6, a pair of leads 180, 182, whichenergize the circuit 48, are encased in suitable insulation to form acable 184 passing through the freezer side wall 16.

The icemaker l affords a number of important advantages previouslymentioned. In addition; the icemaker may be tested for operability priorto installation in a refrigerator.

I claim:

I. An icemaker comprising a mold providing ice piece forming cavities;an ejector mounted for generally vertical movement in the mold betweenan icemaking-ice harvest initiating position and an ice harvestterminating position; a generally vertical rod connected to the ejector;means for vertically moving the rod and the ejector comprising drivingmeans having an output rotatable about a horizontal axis transverse tothe rod, a

' harvest initiating position; and means for stopping the follower atthe nadir.

2. The icemaker of claim 1 wherein the stopping I means comprisescircuit means for de-energizing the driving means between the iceharvest terminating position and the icemaking-ice harvest initiatingposition, and biasing means operative on the follower adjacent thenadir.

3. In an icemaker having a mold, mold cavities, an ejector positionedwithin the mold and being generally vertically movable through the moldcavities between upper and lower positions, and a generally vertical rodconnected to the ejector, the improvement comprising:

an output element having a generally horizontal axis and beingpositioned adjacent the rod and rotatable about the axis;

driving means for rotating the output element;

a member having a generally horizontally extending slot and beingconnected to the rod;

a follower having one end connected to the output element at a locationspaced from the axis and the other end positioned within the slot of themember for moving the ejector between said upper and lower positions inresponse to rotation of the output element; and

a spring connected to the member and positioned at a preselectedlocation in the pathway of the fol- -lower for stopping the rod at apreselected location.

4. An icemaker, as set forth in claim 3, including:

circuit means for selectively energizing the driving means andthereafter de-energizing the driving means at a pre-selected location ofthe rod during downward movement thereof; and

stopping means for stopping the rod at a preselected location adjacentthe lower position of the rod during upward movement of said rod.

5. An icemaker, as set forth in claim 4, wherein the driving means,output element, member, follower, and stopping means are each positionedat a location lower in elevation than the mold.

1. An icemaker comprising a mold providing ice piece forming cavities;an ejector mounted for generally vertical movement in the mold betweenan icemaking-ice harvest initiating position and an ice harvestterminating position; a generally vertical rod connected to the ejector;means for vertically moving the rod and the ejector comprising drivingmeans having an output rotatable about a horizontal axis transverse tothe rod, a member rigid with the rod providing a generally horizontalslot transverse to the axis, a follower rigid with the output spacedfrom the axis thereof and disposed in the slot, the follower defining acircular path of movement having a nadir at the ejector icemaking-iceharvest initiating position; and means for stopping the follower at thenadir.
 2. The icemaker of claim 1 wherein the stopping means comprisescircuit means for de-energizing the driving means between the iceharvest terminating position and the icemaking-ice harvest initiatingposition, and biasing means operative on the follower adjacent thenadir.
 3. In an icemaker having a mold, mold cavities, an ejectorpositioned within the mold and being generally vertically movablethrough the mold cavities between upper and lower positions, and agenerally vertical rod connected to the ejector, the improvementcomprising: an output element having a generally horizontal axis andbeing positioned adjacent the rod and rotatable about the axis; drivingmeans for rotating the output element; a member having a generallyhorizontally extending slot and being connected to the rod; a followerhaving one end connected to the output element at a location spaced fromthe axis and the other end positioned within the slot of the member formoving the ejector between said upper and lower positions in response torotation of the output element; and a spring connected to the member andpositioned at a preselected location in the pathway of the follower forstopping the rod at a preselected location.
 4. An icemaker, as set forthin claim 3, including: circuit means for selectively energizing thedriving means and thereafter de-energizing the driving means at apre-selected location of the rod during downward movement thereof; andstopping means for stopping the rod at a preselected location adjacentthe lower position of the rod during upward movement of said rod.
 5. Anicemaker, as set forth in claim 4, wherein the driving means, outputelement, member, follower, and stopping means are each positioned at alocation lower in elevation than the mold.